Treatment of seasonal affective disorder with a high-output negative ionizer.
J Altern Complement Med. 1995 Jan;1(1):87-92. PMID: 9395604
M Terman, J S Terman
This study was designed to evaluate the antidepressant effect of negative ions in the ambient air as a potential treatment modality for seasonal affective disorder. Twenty-five subjects with winter depression underwent a double-blind controlled trial of negative ions at two exposure densities, 1 x 10(4) ions/cm3 or 2.7 x 10(6) ions/cm3, using an electronic negative ion generator with wire corona emitters. Home treatments were taken in the early morning for 30 min over 20 days, followed by withdrawals. The severity of depressive symptoms (prominently including the reverse neurovegetative symptoms of hypersomnia, hyperphagia, and fatigability) decreased selectively for the group receiving high-density treatment. Standard depression rating scale assessments were corroborated by clinical impressions. When a remission criterion of 50% or greater reduction in symptom frequency/severity was used, 58% of subjects responded to high-density treatment while 15% responded to low-density treatment (chi 2 = 5.00, df = 1, p = 0.025). There were no side effects attributable to the treatment, and all subjects who responded showed subsequent relapse during withdrawal. Treatment with a high-density negative ionizer appears to act as a specific antidepressant for patients with seasonal affective disorder. The method may be useful as an alternative or supplement to light therapy and medications.
Article Published Date : Jan 01, 1995
Rapid and direct mass spectrometric analysis of antibiotics in seawater samples.
Analyst. 2019 Jan 18;:
Authors: He J, Zhang H, Yu K, Qiao L, Li N, Zhang X, Zhang D, Zou M, Jiang J
A method based on droplet spray ionization (DSI) mass spectrometry was described for rapid, direct analysis of seawater samples. By spontaneous desalting (SD) of droplet seawater on a cover slip corner, the target analytes could be separated from the salts. The separated targets are then dissolved in a spray solvent for mass spectrometric analysis. The desorption/ionization of salts is impeded due to their microsolubility or even insolubility in the spray solvent, thus greatly reducing the suppression of ionization of the analyte. It has been demonstrated that the desalting process is spontaneous and highly effective, which simplifies the operation. The dependence of signal intensity on the operation parameters was investigated as well. With this method, a wide range of antibiotics including sulfonamides, macrolides, amphenicols, quinolones, rifamycins, and mixtures in seawater have been successfully detected in either positive or negative ion modes. Limits of detection (S/N ≥ 3) were determined to be 0.52 and 0.20 pg for trimethoprim and clarithromycin, respectively. Moreover, satisfactory accuracy and precision were obtained according to the analysis of real seawater samples. Our results show that the combination of DSI and spontaneous desalting is a simple, sensitive, and rapid method for direct detection of analytes in seawater.
PMID: 30657481 [PubMed - as supplied by publisher]
A New Method Aimed to Quickly Identify Pathogen and Drug Susceptibility Test Based on Matrix-Assisted Laser Desorption/Ionization Time of Flight Mass Spectrometry Combined with Flow Cytometry.
Surg Infect (Larchmt). 2019 Jan 18;:
Authors: Gu YF, Li Y, Zhang XL, Yu LM, Huang BH, Sun CM
AIM: To discuss the significance and applied value in the rapid identification and drug susceptibility test for blood stream infection (BSI) using matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF MS) combined with flow cytometry (FCM).
METHODS: The bacteria were separated from the positive blood culture bottle using the separation gel-adsorption method system, and then applying MALDI-TOF MS combined with FCM to identify pathogen and drug susceptibility test quickly.
RESULTS: The efficiency of the separation gel-adsorption method for gram-negative bacterium, gram-positive bacteria, and fungi is 71%, 74%, and 88%, respectively. The results of identifying pathogens using MALDI-TOFMS are in agreement with results obtained using VITEK®2 (bioMérieux, Marcy l'Etoile, France); both methods can identify 90% of bacteria to species. For fungi, MALDI-TOF MS can identify 75% fungi to species, which is superior to VITEK2, which identifies 60% fungi to species. The results of drug susceptibility test using FCM are almost identical to VITEK2; additionally, the addition of fluorescein diacetate can identify the heterogenic drug-resistant strains.
CONCLUSIONS: We can quickly identify pathogen and drug-susceptibility test based on MALDI-TOF MS combined with FCM, which is consistent with traditional methods and can shorten the report time from 36-72 hour to 3 hours. More importantly, these methods are of great significance and clinical importance for the rapid identification of BSI.
PMID: 30657423 [PubMed - as supplied by publisher]
Short-chain and medium-chain chlorinated paraffins in Canadian house dust and NIST SRM 2585.
Environ Sci Pollut Res Int. 2019 Jan 17;:
Authors: Shang H, Fan X, Kubwabo C, Rasmussen PE
A method for the analysis of short-chain and medium-chain chlorinated paraffins (SCCPs and MCCPs) in house dust was developed. The method is based on sonication extraction, sample cleanup by solid phase extraction (SPE), and separation and detection by gas chromatography coupled with mass spectrometry (GC/MS) operated in electron capture negative ion (ECNI) chemical ionization mode. The method is sensitive, with method detection limits (MDLs) down to 0.22 μg/g for SCCPs and 0.55 μg/g for MCCPs. The overall recoveries of the method were 104 (± 11)% and 108 (± 16)% for SCCPs and MCCPs, respectively. The method was successfully applied to the analysis of SCCPs and MCCPs in NIST standard reference material (SRM 2585, organic contaminants in house dust) and a subset of house dust samples collected under the Canadian House Dust Study (CHDS). Average concentrations of SCCPs and MCCPs in SRM 2585 (n = 12 replicates) were 7.58 (± 0.43) μg/g for SCCPs and 16.4 (± 2.1) μg/g for MCCPs, respectively. A comparison was made between CP concentrations in paired dust samples collected using two different methods from the same homes: fresh or "active" dust (FD) collected by technicians and a sample taken from the household vacuum cleaner (HD). Spearman rank analysis showed a significant positive correlation (p < 0.01) between FD and HD samples for both MCCPs and SCCPs. CPs were detected in every house dust sample (n = 48 HD samples), with median (range) concentrations of 6.2 (4.0 - 57) μg/g and 19 (5.9-901) μg/g for SCCPs and MCCPs, respectively. Widely scattered CP levels and 100% detection frequency in this preliminary set of 48 HD samples suggest a wide variability in Canadian household exposures to CPs.
PMID: 30656583 [PubMed - as supplied by publisher]
Method development and validation of ursodiol and its major metabolites in human plasma by HPLC-tandem mass spectrometry.
Clin Pharmacol. 2019;11:1-13
Authors: Pinto MC, Berton DC, de Oliveira AC, Lazaro CM, Carandina SAC
Background: Ursodeoxycholic acid (UDCA) and its metabolites tauroursodeoxycholic acid (TUDCA) and glycoursodeoxycholic acid (GUDCA) have been the subject of several pharmacological studies. The objective of this study was to develop an innovative method of quantification by HPL-tandem mass spectrometry (LC-MS/MS), with a lower cost and suitable, for application in bioequivalence studies.
Methods: The procedure involved liquid-liquid extraction for quantification of UDCA/GUDCA and precipitation extraction for TUDCA, using deuterated substances as internal standards (ISs) and Phenomenex Luna 250×4.6 mm 5μ C18 100A column. The mobile phase used was acetonitrile/ammonium acetate 30 mM (420: 580 v/v pH 7) for UDCA, acetonitrile/ammonium acetate 10 mM/ammonium hydroxide (400:600: 0.5 v/v/v pH 9) for GUDCA, and acetonitrile/ammonium acetate 10 mM (570: 430 v/v pH 7) for TUDCA. Ions were monitored by the electrospray ion source (ESI) mass spectrometer, operating in a negative ionization mode. Compound determination was performed by LC-MS/MS system using a calibration curve of 15-10,000 ng/mL for UDCA/GUDCA and 5-500 ng/mL for TUDCA. The method was developed and validated according to the Brazilian National Health Surveillance Agency (ANVISA) of Brazil norms harmonized with the main international guidelines as a prerequisite for conducting in vivo study in human volunteers.
Results: The method did not present matrix effect and residual effect, showing to be selective for studied molecules, with adequate accuracy and precision. In addition, the method was considered sensitive presenting a coefficient of variation less than 20% for the lower limit of quantification of each compound.
Conclusion: This method can be applied in bioequivalence studies to determine ursodiol and its metabolites reproducibly, simply, and effectively with the use of readily accessible analytical materials and instrumentation.
PMID: 30655708 [PubMed]
Structural and functional characterization of a bifunctional GH30-7 xylanase B from the filamentous fungus Talaromyces cellulolyticus.
J Biol Chem. 2019 Jan 17;:
Authors: Nakamichi Y, Fouquet T, Ito S, Watanabe M, Matsushika A, Inoue H
Glucuronoxylanases are endo-xylanases and members of the glycoside hydrolase family 30 subfamilies7 (GH30-7) and 8 (GH30-8). Unlike for the well-studied GH30-8 enzymes, the structural and functional characteristics of GH30-7 enzymes remain poorly understood. Here, we report the catalytic properties and 3D structure of GH30-7 xylanase B (Xyn30B) identified from the cellulolytic fungus Talaromyces cellulolyticus Xyn30B efficiently degraded glucuronoxylan to acidic xylooligosaccharides (XOS), including an α-1,2-linked 4-O-methyl-D-glucuronosyl substituent (MeGlcA). Rapid analysis with negative-mode electrospray-ionization multistage MS (ESI(-)-MSn) revealed that the structures of the acidic XOS products are the same as those of the hydrolysates (MeGlcA2Xyln, n > 2) obtained with typical glucuronoxylanases. Acidic XOS products were further degraded by Xyn30B, releasing first xylobiose and then xylotetraose and xylohexaose as transglycosylation products. This hydrolase reaction was unique to Xyn30B, and the substrate was cleaved at the xylobiose unit from its non-reducing end, indicating that Xyn30B is a bifunctional enzyme possessing both endo-glucuronoxylanase and exo-xylobiohydrolase activities. The crystal structure of Xyn30B was determined as the first structure of a GH30-7 xylanase at 2.25 Å resolution, revealing that Xyn30B is composed of a pseudo-(α/β)8-catalytic domain, lacking an α6 helix, and a small β-rich domain. This structure and site-directed mutagenesis clarified that Arg-46, conserved in GH30-7 glucuronoxylanases, is a critical residue for MeGlcA appendage-dependent xylan degradation. The structural comparison between Xyn30B and the GH30-8 enzymes suggests that Asn-93 in the β2-α2 loop is involved in xylobiohydrolase activity. In summary, our findings indicate that Xyn30B is a bifunctional endo- and exo-xylanase.
PMID: 30655295 [PubMed - as supplied by publisher]